Electric tooth brush



FIG. 1 is a top plan view of an electric tooth brush showing my new design;

FIG. 2 is a right side elevation view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a rear elevation view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken line showing of the head and neck illustrate portions of the toothbrush that form no part of the claimed design. 

The ornamental design for an electric tooth brush, as shown and described. 